Method and apparatus for applying a printing plate to a support saddle



E. BERNARD! ETAI- METHOD AND APPARATUS FOR APPLYING A PRINTING Dec. 29,1970 PLATE TO A SUPPORT SADDLE Filed April 2, 1968 4 Sheets-Sheet 1 w m8WD 8 RAZ Y ON a TR NE R W i 0 N n EL 3% 5w 1 Dec. 29, 1970 BERNARDl ETAL 3,550,283

METHOD AND APPARATUS FOR APPLYING A PRINTING PLATE TO A SUPPORT SADDLEFiled April 2, 1968 4 Sheets-Sheet 2 FIG. 2

////////////7777 ////////////LZZ\\\ INVENTOR EUGENE L.BERN RDI RgDOLPHT. BRAZDOVIC I I, f h ATToRr z g Dec. 29, 1970 EL. BERNARDI ETAL3,550,283 METHOD AND APPARATUS FOR APPLYING A PRINTING PLATE TO ASUPPORT SADDLE Filed April 2, 1968 Sheets-$hect 8 INVENTORS EUGENE L.BERNARDI RUDOLPH T. BRAZDOVI i E I 6, ATTORNEY Dec. 29, 1970 BERNARD| ETAL 3,550,283

METHOD AND APPARATUS FOR APPLYING A PRINTING PLATE TO A SUPPORT SADDLE54 FIG. 7 53 v 52 m, L 10mm] I 53mm a r 33 3 so ll! 34 H1 46 :3 W i 4636 h IUINUUINN WNW! {ML-:3 1 :HWL-LZ:11111-513 INVENTORS 37 EUGENE L.BERNARDI RUDOLPH T. BRAZDOVlC RNEYS United States Patent Olhce 3,550,283Patented Dec. 29, 1970 3,550,283 METHOD AND APPARATUS FOR APPLYING APRINTING PLATE TO A SUPPORT SADDLE Eugene L. Bernardi, Oakland, Calif.,and Rudolph T. Brazdovic, Pittstown, N.J., assignors of one-half to WoodIndustries, Inc., Plainfield, N.J., a corporation of Virginia, andone-half to Reichhold Chemicals, Inc., White Plains, N.Y., a corporationof Delaware Filed Apr. 2, 1%8, Ser. No. 718,656 Int. Cl. B41b 1/00 US.Cl. 33184.5 5 Claims ABSTRACT OF THE DISCLOSURE Apparatus for accuratelypositioning the printing portion of a flexible flat printing plate ontoa curved support saddle which apparatus includes a movable layout tablehaving thereon a movable rear register stop adapted to engage with araised reference or printing portion cast on a printing plate topreposition the printing portion of the plate relative to the page to beprinted. Means are provided for rotating the saddle to a preselectedposition such that when the table and plate thereon are moved towardsthe saddle, the underside of the head of the plate will engage thecurved surface of the saddle along a tagent thereto at a desired pointbetween the head and foot of the saddle equal to the position down fromthe top of the page that the top of the printed portion is to appear.Pressure means are provided for imparting a radial pressure to the plateand saddle and rotation means are provided to rotate the saddle and pullthe plate from the layout table.

Method for positioning the printing portion of a flexible flat printingplate onto a curved support saddle including the steps of positioning arear register stop on a layout table depicting the page to be printed ata point equivalent to the position that a raised reference point orpreselected printed matter is to be positioned on the page, bringing aprinting plate having a raised reference portion or preselected printingportion into contact with the stop, circumferentially positioning acurved support saddle at a point where the bottom surface of the headend of the plate may engage the saddle along a tangent thereto at apoint which is a predetermined distance from the head of the saddle,moving the table and plate towards the saddle such that the plateengages the saddle along a tangent thereto, and applying a radial forceto the saddle plate at the point of tangency while rotating the saddleto withdraw the plate from the table.

BACKGROUND OF THE INVENTION This invention relates to a printing plateapplicator and more particularly to apparatus and method by which a thinprinting plate may be accurately affixed to a curved support saddle.

It is necessary in multi-color printing that a separate printing platebe provided for each color printed which in turn requires that each ofthe several plates be accurately positioned on the printing cylinders ofa press if the colors when printed are to accurately register withoutundesirable overlap.

Heretofore, the production of color printing plates and the positioningof the plate in printing press equipment has involved complex andtime-consuming operations to assure accurate registry. The time requiredto prepare and position the plates is of major importance when rotarycylinder type press equipment is used such as in the printing ofnewspapers where minimum setup time is of extreme importance.

It has been the usual practice when preparing plates for color printingto photograph the original copy utilizing suitable filters in order thatseparate photographic prints may be made of the copy in each of thebasic colors to be printed. Register marks in the form of cross hairs orbulls-eye markings are applied to the margin of the original copyutilizing register bars and these marks in turn are transferred to eachof the photographic prints. The prints are then reduced to metal orplastic plates by conventional photo-chemical or mechanical means withthe register markings on the prints being transferred at the same time.The engraver then utilizes the register marks on the plates to cut andtrim the four sides of the plates to assure that all of the plates willregister accurately with one another.

These etched or engraved plates are then placed in a printing form orchase utilizing the register bars to assure accurate positioning in theform. This is usually accomplished by having four holes drilled in theregister bars. These holes are then transferred to a block or base whichis 'fitted in the form and pins then are inserted into the holes inorder that each of the engraved plates may be successively positioned inthe form. A matrix is molded from each plate while in the form afterwhich it is removed and carefully trimmed. Each matrix is then carefullypositioned in a stereotype plate casting machine from which a heavymetal plate is cast. This metal plate is then accurately machined tosize and any dead or unwanted portions of the plate are routed out.

This manner of producing the individual metal printing plates necessaryto produce a single color print is timeconsuming, expensive and subjectto errors. For example, the pins positioning the engraved plates in theprinting form may become bent such that the plates will becomemisaligned in the form. The matrices must be carefully dried in order tocontrol shrinking and must be carefully trimmed to size, itself adiflicult procedure. Further the matrices must be carefully positionedin the casting box. Any error in any of the above steps can result infaulty printing.

We propose to overcome many of the difii'culties inherent in theconventional casting of stereotype metal printing plates by utilizing athin flexible plastic printing plate which may be cast in a fiatposition in a casting machine having therein a matrix for each colorplate made from the original copy and on which a reference mark, forexample a margin line, has been noted. The plastic plate cast from themachine is then accurately positioned onto a layout table by utilizing araised reference or printing portion cast onto the plate and whichcorresponds to the reference mark on the original copy and the plate isthen transferred to a support saddle which is applied directly to theprinting cylinder of a printing press. This use of a raised reference orprinting portion of all the plates of a multi-color print as a basepoint from which to position the plates eliminates the need forincorporating any holes in the base of a printing form and the attendantuse of setting pins, any precise trimming of mats, any criticalplacement of mats in a stereotype plate casting machine or of trimmingthe sides of the cast printing plate. Further, if more than one printingplate is to be cast, it merely involves using the same casting machinewith the same matrices so that the plates cast from a single matrix areuniform.

Broadly our invention is directed to an apparatus and method by which athin printing plate is applied to a curved support saddle so as toassure accurate positioning of the plate on the saddle both incircumferential and axial directions. The apparatus includes a rotatablecylinder which is identical in diameter to the printing cylinder of apress and to which a curved support saddle is held by holding meanssimilar to the holding means by which the saddle is to be locked to theprinting cylinder. The outer curved surface of the saddle has anadhesive thereon and means in the form of a pressure roll are providedsuch that when one end of a printing plate is brought into contact withthe saddle, the printing plate may be rolled onto the saddle when thesaddle cylinder is rotated relative to the pressure roll. Adjustablestop and index means are associated with the saddle cylinder so that thecircumferential point of initial contact of the top end of the printingplate will be circumferentially positioned on the saddle and willcorrespond to a pre-set distance from the top of a printed page. Amoveable flat layout table is provided such that the printing portion ofa flat printing plate may be accurately positioned laterally withrespect to the saddle to provide column register and also such that theprinting portions adjacent the tail end of the plate may bepre-positioned with respect to a base line which in turn turn ispositioned relative to the distance from the top of the printed page tobe printed. The table is moveable with respect to the saddle cylindersuch that the top edge of the printing plate carried by the table may bebrought into engagement with the outer adhesive surface of the saddlealong a tangent thereto and at a point where the pressure rolls forms anip with the saddle. Means are provided for rotating the cylinder suchthat the plate may be pulled from the layout table and rolled onto thesaddle by the application of a radial force of the pressure roll.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a broken side view of a plateapplicator constructed according to the invention;

FIG. 2 is a perspective view illustrating a saddle to which a printingplate is to be affixed;

FIG. 3 is a perspective view illustrating means for locking the saddleof FIG. 2 onto a saddle cylinder of the plate applicator;

FIG. 4 is an end view of the saddle cylinder of FIG. 3 and a portion ofthe applicator illustrating an adjustable stop means forcircumferentially positioning the cylinder of FIG. 3;

FIG. 5 is a plan view of the stop means of FIG. 4 shown associated withan index means carried on the cylinder;

FIG. 6 is a sectional view of FIG. 5 taken along lines VIVI;

FIG. 7 is a plan view of a portion of the applicator shown in FIG. 1 andmore particularly a layout table; and

FIG. 8 is an enlarged sectional view taken along lines VIII-VIII of FIG.7 illustrating a register means for positioning a printing plate on thelayout table.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1there is illustrated a plate applicator 1 having a plate applicatorportion 2 and a layout table portion 3 on which a thin flexible plasticprinting plate P having a head or top end and a tail or bottom end maybe accurately positioned. The applicator portion 2 comprises a rotatablesaddle cylinder 4 of the same diameter as the printing cylinder of aprinting press to which the saddle is to be affixed. The cylinder 4 isrotated about its shaft 5 by a drive means 6 which connects with theshaft by a drive chain 7.

As shown in FIGS. 2 and 3, the saddle S to which the thin printing plateP is to be attached comprises a semicircular member which is attached tothe cylinder 4 by means of a fixed clamp 8 and movable clamps 9 whichare slidable in tracks 10 contained on the surface of the saddlecylinder and which extend parallel to the cylinder axis. The saddle alsohas head and tail ends corresponding in direction to the head and tailends of the plate P. Clamps 9 are moved in their tracks 10 by threadedscrews 11 which are turned by knobs 12 to force an end of the plate intocontact with the fixed clamp 8 and thus lock the saddle to the cylinder.Additional clamping pressure is obtained by lock-up rods 12' acting oncam discs 13 and 14. These clamps are identical with clamps on theprinting cylinder of the printing press which are utilized to secure thesaddle to the printing cylinder.

The cylinder 4 is further provided with a locating bar 15 adapted toengage one circumferential end of a saddle such that the saddle will becircumferenially positioned with respect to the cylinder prior to theapplication of the holding clamps.

While we have illustrated in FIGS. 2 and 3 a saddle which is adapted tobe held to a printing cylinder by end clamps, it is obvious that thesaddle could be afiixed to the cylinder by other lock-up devices whichare similar to the lock-up devices for securing the saddle to theprinting cylinder of a press. For example, conventional undersidetension lock-uphooks may be used which would engage recesses or pocketscut into the under surface of the saddle. The cylinder 4 would then havesimilar underside tension lock-up hooks on its surface positioned in thesame manner as tension lock-up hooks in the printing cylinder to whichthe saddle is eventually to be applied. In such an arrangement, it wouldnot be necessary to include the locating bar 15 on the saddle cylinderas the register hooks would serve to circumferentially acuratelyposition the saddle onto the cylinder 4. The advantage of using the sametype lock-up devices on the cylinder of the applicator as on thecylinder of the press is that the chance of plate misalignment when thesaddle is applied to the press is reduced.

The applicator portion further comprises a pressure roll 16 which isrotatably carried on an arm 17 which in turn is pivotable about a shaft18. Arm 17 is connected by crank 19 to a piston rod 20 of a fluid motor21 such that when the piston rod 20 moves in an upward direction asshown in FIG. 1, the roll 16 will be moved in a counterclockwisedirection to exert a radial force on the printing plate P to force itinto intimate contact with the surface of the saddle S to which anadhesive, preferably a double-faced adhesive sheet, has been previouslyapplied.

The plate P is preferably of a thin, light flexible plastic materialwhich can be rolled around the surface of the saddle without crackingwhen the cylinder 4 is rotated in a clockwise direction by the drivemeans 6.

It is necessary that the plate P be accurately positioned on the surfaceof the saddle to assure that when the saddle is applied to a printingcylinder of a pressure, the plate will be in accurate registry withother color plates applied to other cylinders. This requires that theplate be accurately positioned both longitudinally and circumferentiallywith respect to the saddle.

Circumferential positioning of the printing plate on the saddle isaccomplished by pre-setting the rotational position of the saddlecylinder such that the top or head end of the printing portion of theprinting plate when brought into position to contact the adhesivesurface of the sad dle as shown in FIG. 1 will be at a pre-set distancefrom the top of the page on which the plate will eventually print. Thisis achieved by rotating the cylinder 4 in a clockwise direction as shownin FIG. 1 until a retractable plunger 22 shown in FIGS. 4, 5 and 6,engages a stop surface 23 on adjustable bracket 24. The bracket 24 has acurved slot 25 therein through which screws 26 extend for adjustablysecuring the bracket to the saddle cylinder. It is seen by reference toFIG. 4, that as the bracket 24 is moved counterclockwise with respect tothe cylinder, that the point of engagement of the stopping surface 23with the plunger 22 will be moved toward the left end fo the saddlewhich is adjacent the top of the page to be printed. Conversely, if thebracket 24 is moved clockwise with respect to the cylinder 4, the pointof engagement will be moved closer toward the right end of the saddleadjacent the bottom of the page to be printed.

Precise positioning of the saddle cvlinder is accomplished by utilizinga scale 27 contained on the end of the cylinder which is calibrated toindicate the distance of the bottom edge of a raised reference orprinting portion of the plate from the top of the page to be printed.The scale is conveniently marked in inches taking into ac- :ount anychange of dimension that may exist between the page as printed and theactual dimensions of the plastic plate.

Plunger 22 is connected to a piston inside an air cylinder 28 such thatthe plunger may be fully retracted in the event it is desired to rotatethe cylinder past the adjustable stop means when removing or applying asaddle.

Referring to FIGS. 7 and 8, there is illustrated a moveable layout table3 on which the flat printing plate is initially layed out and positionedrelative to the page which is to be printed. The table 3 has a tablesurface 30 which is large enough to accommodate a single plate of fullpage size. Surface 30 has thereon two longitudinally extending slots 31which serve as guides for a movable rear register bar 32 and a lateralslot 33 in which side register units 34 may slide to engage the raisedprinting portion of a printing plate.

Scales 35 are provided on both sides of the table from which the stopbar may be positioned. The scales are preferably calibrated in inches tomeasure the effective length of the fiat printing plate. Thus if a platehaving an effective length 12 inches long is to be applied to a saddle,the rear register bar is set at the 12 inches on the scales. Thisassures that the head or top edge of the plate will overhang the end ofthe table a predetermined amount, as shown in FIG. 1, and will engagethe saddle along a predetermined line when the cylinder is set at apredetermined position and when the table is moved toward the cylinder.In this manner, the top of the printing portion of the printing platewill be positioned a predetermined distance from the top of the page tobe printed.

The rear register bar has thereon screws 36 which are threade intoblocks 37 which in turn slide on the slots 31. In this manner, the rearregister bar may be locked into position by turning screws 36.

The rear register bar 32 comprises in part a stop 38 adapted to engagean edge 39 of the printing plate which forms the bottom end of theprinting portion of the plate. This edge is cast with the printingportion of the plate and provides an accurate base line from which tomeasure the length of the printing portion, i.e., effective length ofthe printing plate. The stop overhangs a bottom slide portion 40 of thebar 32 and also a dead portion 41 of the plate which usually comprisesexcess flashing resulting from the casting operation and which comprisesa nonprinting portion of the plate. This mode of engagement of the platewith the rear register bar eliminates any need of the edges of the platebeing accurately trimmed after it is cast since the point from which themeasurement of the plate is made used in positioning the plate on thesaddle is cast along with the printing portion.

A plurality of undercut clamps 45 are slidably positioned along the bar32 to hold the plate in position once the stop engages the edge 39. Theclamps are provided with screws 46 in order that they may be locked inplace. A spring biased ball 47 is contained in a threaded stud 48carried by the clamp in order to hold the plate firmly down on thesurface 30 of the table. In addition, the top of the two outer clampshave reference lines (not shown) on the top thereof which are even withthe end of the margin bar whereby the position of the end of the marginbar may be read on the scales 35.

The layout table is also provided with column lines 49 similar to thecolumn lines on the page to be printed. By utilizing these column lines,the plate may be positioned laterally with respect to the table by theuse of side units 50. Side units 50 are generally similar to units 45and include the margin stop arrangement for engaging a side of theprinted portion similar to edge 39. Side units 34 also have a marginstop arrangement for accurately positioning the top portion of theprinting plate.

The table 3 is mounted on slides 52 carried by the frame of theapplicator such that it may be manually moved towards and away from thesaddle cylinder. When the table is moved to the position where shoulder53 on the frame contacts shoulder 54- of the table, the top end of theplate will be in line contact with the saddle.

The procedure for setting a plate on a saddle is as follows. Theoperator first positions the fiat plate on the layout table relative tothe page which is to be printed. For example, if the plate is for acolor print three columns wide between columns 2 and 6 of the page andthe print is twelve inches long with the top of the print to be twoinches down from the top of the page, the rear register bar '32 is setat 12 inches on scale 35 with the margin stop 38 of the bar 32 engagingthe edge of the printing portion. The side register units 34 and 45 arethen moved into position such that their stops coincide with columnlines 2 and 6. The screws of all clamps are then tightened. In the eventthat the matter to be printed does not have a printed portion at thebottom such that the printing plate would not normally have acorresponding printing portion which would be engaged with a stop 38,such a portion could nevertheless be cast with the plate from areference mark made on the original copy such that it would appear onall plates of the same color scene and subsequently be routed out afterthe plate has been applied to a saddle.

The adjustable stop on the cylinder is then set to fourteen inches onscale 27 (12 inches length of plate plus two inches from top of plate totop of page) and the cylinder rotated until plunger 22 engages againststop surface 23 which circumferentially locates the circumferentialportion of the saddle at which the top end of a plate will engage thesaddle. The saddle is then clamped onto the saddle cylinder and adhesiveapplied to the outer surface thereof. The layout table 3 is then movedtowards the saddle cylinder until the shoulders 53 and 54 engage atwhich position the top inner edge of the plate will contact the outersurface of the saddle. Fluid motor 21 is then actuated bringing pressureroll 16 down onto the plate to force the plate into intimate contactwith the adhesive surface on the saddle. Drive means 6 is then actuatedwhich rotates cylinder 4 pulling the plate P from table 3 between theroll 16 and saddle whereby the plate is rolled smoothly and evenly ontothe saddle. Subsequent plates for the remainder of the colors of theprint may be applied to saddles without change of the settings of theadjustable stops and rear register bar which further assures that allplates will engage their saddles in the same positions thus promotingaccurate registry of the several colors when printed.

While we have described a preferred embodiment of our invention, it isobvious that minor changes could be made and still come Within the scopeof the invention. For example, the layout table instead of being movablealong a straight line towards the saddle cylinder, could move towardsthe cylinder by a pivotable action whereby the end of the plate would bepivoted into the position shown in a dotted line in FIG. 1. Further, thelayout table and adjustable stop means could be mounted on a presswhereby the plate would be aflixed to a saddle mounted on a printingplate cylinder.

Also instead of using the specific undercut clamps 45 as illustrated inthe drawings, other clamps could be used which could have a stop similarto 38 thereon for engaging and positioning a plate. For example, a stopsimilar to 38 could be mounted directly to an adjustable clamp whichcould be adjustably positioned with respect to the plate.

We claim:

1. A printing plate applicator for applying a thin flexible printingplate having a tail end, a head end and an under surface to a curcedsupport saddle where the printing plate has a raised reference portionthereon adjacent the tail end of the plate, raised printing portionsthereon and non-printing portions thereon, said applicator comprising arotatable cylinder adapted to mount a saddle, rotation means forrotating said cylinder, locating and locking means on said cylinder forcircumferentially positioning and locking a saddle thereon, adjustablestop means for limiting rotational movement of said cylinder, a movablelayout table having a top end adapted to support said printing plate,rear register means on said table for accurately positioning saidprinting plate thereon to provide a predetermined overhang of the headend of a plate over the top end of the layout table including a rearregister stop spaced vertically above said table a distance greater thanthe thickness of the non-printing portions of the plate and less thanthe raised reference portion on the plate whereby said stop may overliea nonprinting portion of said plate to engage a side of the raisedreference portion, means mounting said table for movement towards saidcylinder whereby the under surface of the head end of a plate may engagea curved saddle along a tangent thereto, and pressure means spaced fromand extending parallel to said cylinder for exerting a radial pressureon a printing plate at the point of tangential engagement of the plateand saddle to urge the plate into firm engagement with the saddlewhereby rotation of the saddle will draw the plate from the layouttab-1e.

2. A printing plate applicator according to claim 1 having in addition afirst index scale on said cylinder calibrated in units of distance fromthe top of the page to be printed to the top of the printed matter to beincluded on the page by which said adjustable stop means is positionedcircumferentially with respect to said cylinder whereby the initialpoint of tangential engagement on a saddle by a plate may bepredetermined when said table and a plate thereon are moved towards asaddle.

3. A printing plate applicator according to claim 2 wherein said layouttable includes a second index scale and a marker associated with therear register means with said scale calibrated to measure units oflength of plate from an edge of a raised printed portion adjacent thehead end of the plate to a raised reference portion and wherein thedistance from the rear register means to the top end of the table at anysetting of the marker on the second index scale is less than the readingon the second scale by an amount equal to the predetermined overhang ofthe head portion of a plate when the rear register stop engages theraised reference portion on the plate.

4. A method of accurately positioning and affixing a series of thinprinting plates making up a single multicolor scene to be printed onto aplurality of curved support saddles wherein each plate has a tail end, ahead end,

a raised printing portion and an under surface and each said saddle hasa head end comprising the steps of casting a raised reference portiononto each printing plate near the tail end thereof wherein eachreference portion in the series is in the same position with respect tothe printing portion of each of the plates, positioning a raised rearregister stop on a page layout table having a top end where the distancebetween the stop and the top end of the table is equal to the distancebetween the raised reference portion and the edge of the printingportion adjacent the head end of each plate less a predetermineddistance equal to a predetermined overhang of the head end of a plateover the top end of the layout table when the rear register stop engagesthe raised reference portion of a plate, successively for each platecircumferentially positioning a saddle such that the under surface of ahead end of a plate will engage the outer surface of the saddle along atangent thereto at a point which is at a predetermined distance from thehead end of the saddle which distance is equal to the distance from thetop of the page to be printed to the printed matter to be printed by theplate, positioning a plate on the table such that the raised rearreference stop engages the raised rear reference portion on the plate,moving said table relative to said saddle so that the under surface ofthe head end of the plate will engage the outer surface of the saddlealong a tangent thereto, and rotating said saddle circumferentially awayfrom said table to pull the plate from the table.

5. A method according to claim 4 including the additional step ofapplying pressure to said plate in a radial direction with respect tosaid saddle while rotating said saddle and drawing said plate from saidtable to insure firm engagement between the saddle and plate.

References Cited UNITED STATES PATENTS 1,650,132 11/1927 Jones 101-426UX2,668,363 2/1954 Lippitt 33 184.5 2,689,411 9/1954 Huck 33-184.52,736,259 2/1956 Sather 101378 2,900,735 8/1959 Mier 33184.5 2,901,8329/1959 Hulen 33184.5 2,990,000 6/1961 Mangus et al. 101415.1UX 3,090,1295/1963 Gifford 33184.5 3,158,943 12/1964 Benson 33184.5 3,206,859 9/1965Walsh 33184.5

FOREIGN PATENTS 775,399 5/1957 Great Britain 10l426 ROBERT E. PULFREY,Primary Examiner C. D. CROWDER, Assistant Examiner US. Cl. X.R.

